NationMaster - Encyclopedia: Green roof

A green roof is a roof of a building that is partially or completely covered with vegetation and soil, or a growing medium, planted over a waterproofing membrane. The term does not include roofs which are merely colored green, as with green shingles. It may also include additional layers such as a root barrier and drainage and irrigation systems. Container gardens on roofs, where plants are maintained in pots, are not included in this discussion, as they are not considered true green roofs (though this is an area of debate). The term Green Roof can also be applied to roofs that have some form of purpose considered "green", such as solar panels or a photovoltaic module. Green roofs are also referred to as eco-roofs, living roofs or greenroofs (a more grammatically correct terminology) Image File history File linksMetadata Download high resolution version (2272x1704, 1154 KB) File links The following pages link to this file: Vinland Viking LAnse aux Meadows Leif Ericson Green roof Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize... Image File history File linksMetadata Download high resolution version (2272x1704, 1154 KB) File links The following pages link to this file: Vinland Viking LAnse aux Meadows Leif Ericson Green roof Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize... The term Viking commonly denotes the ship-borne explorers, traders, and warriors of the Norsemen (literally, men from the north) who originated in Scandinavia and raided the coasts of the British Isles, France and other parts of Europe as far east as the Volga River in Russia from the late... Labrador (also Coast of Labrador) is a region of Atlantic Canada. ... Image File history File links Bour_Faroe_Islands_closer. ... Image File history File links Bour_Faroe_Islands_closer. ... BÃ¸ur is a villige in the Faroe Islands. ... A roof tiled in imitation of thatch at Croyde, north Devon, England Rooftops in Vietnam Snow on the roof The roof, the top covering of a building, is one of the universal structures found on all buildings. ... For other uses, see Building (disambiguation). ... Solar Panel made by BP Solar The solar panels (photovoltaic arrays) on this small yacht at sea can charge the 12 V batteries at up to 9 Amps in full, direct sunlight. ... A laundromat in California with flat-plate solar water heating collectors on its roof. ...

Benefits of green roofs

A green roof is often a key component of an autonomous building. photo of a backyard A yard is an enclosed area of land, usually tied to a building. ... A patio of the Livadia Palace in Crimea. ... All-air and air-water HVAC systems use air ducts, outlets, and inlets installed throughout their buildings. ... Unsolved problems in physics: What causes anything to have mass? The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S. Mass is the property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... Evaporative cooling is a system in which latent heat of evaporation is used to carry heat away from an object to cool it. ... A terrarium is a clear container (often plastic or glass) used to grow plants and to examine or hold small creatures. ... An urban heat island (UHI) is a metropolitan area which is significantly warmer than its surroundings. ... Stormwater is a term used to describe water that originates during precipitation events. ... Xeriscaping, a word coined by combining xeros (Greek for dry) with landscaping, is a water-conservative approach to landscaping. ... Many of the compounds which are dangerous to the environment can also be harmful to humans in the long-term range and come from mineral and fossil sources or are produced by humans themselves. ... Carbon dioxide is an atmospheric gas composed of one carbon and two oxygen atoms. ... A living wall or Folkewall is a vertical garden. ... Where appreciation for the importance of biodiversity meets the New Urbanism, youll find the pursuit of the creation of urban wilderness. ... It has been suggested that this article or section be merged with Off-the-grid. ...

According to Green Roofs for Healthy Cities (a network of public and private interests founded by Steven W. Peck based in Toronto): Motto: Diversity Our Strength Map of Ontario Counties, Toronto being red Area: 641 sq. ...

A 2005 study by Brad Bass of the University of Toronto showed that green roofs can also reduce heat loss and energy consumption in winter conditions.[1] World map showing North America A satellite composite image of North America. ... This article is 150 kilobytes or more in size. ... The University of Toronto (U of T) is a coeducational public research university in Toronto, Ontario. ...

History and uses of green roofs

Modern green roofs, which are made of a system of manufactured layers deliberately placed over roofs to support growing medium and vegetation, are a relatively new phenomenon. They were developed in Germany in the 1960s, and have since spread to many countries in Europe. Today, it’s estimated that about 10 percent of all German roofs have been “greened.” [2] The United States has some green roofs, but they are not as common as in Europe.

Many green roofs are installed to comply with local regulations and government fees, often regarding stormwater runoff management.^[1] In areas with combined sewer-stormwater systems, heavy storms can overload the wastewater system and cause it to flood, dumping raw sewage into the local waterways. Green roofs decrease the total amount of runoff and slow down the rate of runoff flowing off the roof. It has been found that they can retain up to 75 percent of rainwater, gradually releasing it back into the atmosphere via condensation and transpiration, while retaining pollutants in their soil. [3] Elevation 314, a new development in Washington D.C., uses green roofs to filter and store some of its stormwater on site, avoiding the need for expensive underground sand filters to meet D.C. Department of Health stormwater regulations.

Combating the urban heat island effect [4]is another reason for creating a green roof. Traditional building materials soak up the sun's radiation and reflect it back as heat, making cities at least 7 degrees hotter than surrounding areas. [5] On Chicago's City Hall, by contrast, which features a green roof, temperatures on a hot day are typically 25–80 degrees Fahrenheit (14–44 degrees Celsius) cooler than they are on traditionally roofed buildings nearby. [6]

Green roofs are becoming common in Chicago, as well as Atlanta, Portland, and other cities, where regulations to combat the urban heat island encourage their use. In the case of Chicago, the city has passed codes offering incentives to builders who put green roofs on their buildings. The Chicago City Hall green roof is one of the earliest and most well known examples of green roofs in the United States; it was planted as an experiment to determine the effects a green roof would have on the microclimate of the roof. Following that and other studies, it has now been estimated that if all the roofs in a major city were "greened," urban temperatures could be reduced by as much as 12 degrees . [7]

Green roofs have also been found to make dramatic improvements in a roof’s insulation value. A study conducted by Environment Canada found a 26 percent reduction in summer cooling needs, and a 26 percent reduction in winter heat losses when a green roof is used. [8] In addition, greening a roof is expected to lengthen a roof’s lifespan by two or three times, according to Penn State University’s Green Roof Research Center. [9]

Finally, green roofs provide habitat for plants, insects and animals that otherwise have limited natural space in cities. Even in high-rise urban settings as tall as 19 stories high, it has been found that green roofs can attract beneficial insects, birds, bees and butterflies. Rooftop greenery complements wild areas by providing "stepping stones" for songbirds, migratory birds and other wildlife facing shortages of natural habitat. [10]

Types of green roof

Green roofs can be categorised as "intensive", "semi-intensive" or "extensive", depending on the depth of planting medium and the amount of maintenance they need. Traditional roof gardens, which require a reasonable depth of soil to grow large plants or conventional lawns, are labour-intensive, requiring irrigation, feeding and other maintenance. "Extensive" green roofs, by contrast, are designed to be virtually self-sustaining and should only require a minimum of maintenance, perhaps a once-yearly weeding or an application of slow-release fertiliser to boost growth. They can be established on a very thin layer of "soil" (most use specially formulated composts): even a thin layer of rockwool laid directly onto a watertight roof can support a planting of Sedum species and mosses. Image File history File links Green_City. ... Image File history File links Green_City. ... The Borough of Manhattan, highlighted in yellow, lies between the East River and the Hudson River. ... A roof garden is any garden on the roof of a building. ... Mineral wool, also known as mineral cotton, silicate cotton, stone wool, slag wool, rockwool, and rock wool, is an inorganic substance used for insulation and filtering. ... Species See text Sedum is a large genus of the Crassulaceae, representing about 400 species of leaf succulents, found throughout the northern hemisphere, varying from annual groundcovers to shrubs. ...

Another important distinction is between pitched green roofs and flat green roofs. Pitched green roofs are a traditional feature of many Scandinavian buildings and they tend to be of a simpler design than flat green roofs. This is because the pitch of the roof reduces the risk of water penetrating through the roof structure allowing fewer waterproofing and drainage layers to be used.

Brown roofs

Industrial brownfield sites can be valuable ecosystems, supporting rare species of plants, animals and invertebrates. Increasingly in demand for redevelopment, these habitats are under threat. "Brown roofs" can partly mitigate this loss of habitat by covering the flat roofs of new developments with a thin layer of crushed rubble and gravel, ideally obtained at minimal cost from the redevelopment site itself. They are intended to be gradually colonised by spiders and insects and provide a feeding site for insectivorous birds. Laban, a centre for contemporary dance in London, has a brown roof specifically designed to encourage the locally rare black redstart. (In 2003 Laban won the coveted RIBA Stirling Prize.) There are similar brown roofs on several nearby buildings in Deptford, including the Creekside Education Centre. In town planning, brownfield land is an area of land previously used or built upon, as opposed to industry or mining and therefore may be contaminated by hazardous waste or pollution. ... The Laban Dance Centre in Deptford, south-east London opened in February 2003. ... This article is about the capital of England and the United Kingdom. ... Binomial name Phoenicurus ochruros (S. G. Gmelin, 1774) The Black Redstart (Phoenicurus ochruros) is a small passerine bird that was formerly classed as a member of the Thrush family (Turdidae), but is now more generally considered to be an Old World flycatcher (Muscicapidae). ... Riba is the (Arabic: Ø±Ø¨Ø§ ) term for intrest, the charging of which is forbidden by the Quran here, among other places: And that which you give in gift (loan) (to others), in order that it may increase (your wealth by expecting to get a better one in return) from other... 30 St Mary Axe (London, England). ... Deptford is an area of the London Borough of Lewisham, on the south bank of the River Thames in south-east London. ...

Examples of green roofs

One of the largest expanses of extensive green roof is to be found in the USA, at Ford Motor Company's River Rouge Plant, Dearborn, Michigan, where 42,000 square metres (454,000 ft²) of assembly plant roofs are covered with sedum and other plants. Other well-known American examples include Chicago’s City Hall and the Gap headquarters in San Bruno, Calif. The cities of Chicago, Atlanta and Portland, Ore., also boast numerous green roofs.[11] Image File history File linksMetadata Green_Roof_at_VendÃ©e_Historial,_les_Lucs. ... Image File history File linksMetadata Green_Roof_at_VendÃ©e_Historial,_les_Lucs. ... It has been suggested that this article be split into articles entitled Ford Motor Company and Ford (vehicles). ... Aerial view of the Rouge complex in 1942 Interior of the Rouge Tool & Die works, 1944 The River Rouge Plant (commonly known as the Rouge Complex or just The Rouge) is a Ford Motor Company automobile factory complex located in Dearborn, Michigan at the confluence of the Rouge and Detroit... Dearborn may refer to: Dearborn, Michigan Dearborn County, Indiana Dearborn, Missouri Fort Dearborn (Present-day Chicago) This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... Official language(s) None (English, de-facto) Capital Lansing Largest city Detroit Area Ranked 11th - Total 97,990 sq mi (253,793 kmÂ²) - Width 239 miles (385 km) - Length 491 miles (790 km) - % water 41. ... Species See text Sedum is a large genus of the Crassulaceae, representing about 400 species of leaf succulents, found throughout the northern hemisphere, varying from annual groundcovers to shrubs. ...

Switzerland has one of Europe's oldest green roofs, created in 1914 at the Moos lake water-treatment plant, Wallishofen, Zürich. Its filter-tanks have 30,000 square metres (320,000 ft²) of flat concrete roofs. To keep the interior cool and prevent bacterial growth in the filtration beds, a drainage layer of gravel and a 15 cm (6 in) layer of soil was spread over the roofs, which had been waterproofed with asphalt. A meadow developed from seeds already present in the soil; it is now a haven for many plant species, some of which are now otherwise extinct in the district, most notably 6,000 Orchis morio (green-winged orchid). More recent Swiss examples can be found at Klinikum 1 and Klinikum 2, the Cantonal Hospitals of Basel, and the Sihlpost platform at Zürich's main railway station. ZÃ¼rich (German: , ZÃ¼rich German: ZÃ¼ri , in English generally Zurich, Italian: Zurigo) is the largest city in Switzerland (population: 366,145 in 2004; population of urban area: 1,091,732) and capital of the canton of ZÃ¼rich. ... Base layer of asphalt concrete in a road under construction. ... Green Winged Orchid: Orchis morio of th family Orchidaceae. ... The twenty-six cantons of Switzerland are the states of the federal state of Switzerland. ... Basel (British English traditionally: Basle and more recently Basel , German: Basel , French: BÃ¢le , Italian: Basilea ) is Switzerlands third most populous city (166,563 inhabitants (2004); 690,000 inhabitants in the metropolitan area stretching across the immediate cantonal and national boundaries made Basel Switzerlands second-largest urban area...

What is believed to be the world's first green roof botanic garden was set up in Augustenborg, a suburb of Malmö, in May 1999. The International Green Roof Institute (IGRI) opened to the public in April 2001 as a research station and educational facility. (It has since been renamed the Scandinavian Green Roof Institute (SGRI), in view of the increasing number of similar organisations around the world.) Green roofs are well-established in Malmö: the Augustenborg housing development near the IGRI botanic garden incorporates green roofs and extensive imaginative landscaping of streams, ponds and soakaways between the buildings to deal with storm water run-off. The new Bo01 urban residential development (in the Västra Hamnen (Western Harbour) close to the foot of the iconic Turning Torso office and apartment block, designed by Santiago Calatrava) is built on the site of old shipyards and industrial areas, and incorporates many green roofs. Inside the United States Botanic Garden Botanical gardens grow a wide variety of plants both for scientific purposes and for the enjoyment and education of visitors. ... Coat-of-arms of Augustenborg municipality in Denmark. ... Motto: FrÃ¥n arbetarstad till kunskapsstad (eng: From industrial city to knowledge city) Location of MalmÃ¶ in northern Europe Coordinates: Country Sweden Municipality MalmÃ¶ Municipality County SkÃ¥ne Province Scania Charter 13th Century - Mayor Illmar Reepalu Area - City 335. ... HSB Turning Torso is a skyscraper in MalmÃ¶, Sweden on the Swedish side of the Oresund strait. ... Womens Bridge, in Puerto Madero, Buenos Aires. ...

British examples can be found at the University of Nottingham Library, and in London at the Horniman Museum and Canary Wharf. The Ethelred Estate, close to the River Thames in central London, is the British capital's largest roof-greening project to date. Toxteth in Liverpool is also a candidate for a major roof-greening project. The University of Nottingham is a leading research and teaching university in the city of Nottingham, in the East Midlands of England. ... Categories: Museum stubs | London attractions ... HSBC Tower (left), One Canada Square (centre), Citigroup Centre (right) Canary Wharf in Tower Hamlets, London, England, is a large business development on the Isle of Dogs, centred on the old West India Docks in the London Docklands. ... Several places exist with the name Thames, and the word is also used as part of several brand and company names Most famous is the River Thames in England, on which the city of London stands Other Thames Rivers There is a Thames River in Canada There is a Thames... A picture of some derelict terraces in Toxteth. ... Liverpool skyline. ...

In France, a huge green roof of roughly 8,000 m² (70,000 ft²) has been incorporated into the new museum L'Historial de la Vendée which opened in June 2006 at Les Lucs-sur-Boulogne.

Disadvantages of green roofs

Some disadvantages that have been found in the use of green roofs include the need to strengthen the structural support of some existing roofs being retrofit to accommodate a green roof, and the fact that green roof vegetation is often not designed to be walked on by humans. Since most green roof designs originate in Europe, it is also sometimes necessary to adapt those designs for the differing climatic conditions of other areas. [12]

Green roofs have more demanding structural standards. Many existing buildings cannot be retrofitted to have a green roof because of the weight load requirements for the soil and vegetation. A concrete roof deck makes a green roof much more feasible, as opposed to a metal or wood roof deck. Green roofs also have more exacting standards for the roof system to be installed beneath it, as finding and repairing a leak under 4-12 inches of soil and vegetation is an expensive endeavor.

Green roofs in Egypt

In Egypt, soil-less agriculture is used to grow plants on the roofs of buildings. No soil is put directly on the roof itself, thus eliminating the need for an insulating layer. The plants are grown on wooden tables. Vegetables and fruit are the most popular candidates, providing the family with a fresh, healthy source of food that is free from chemicals.

A more advanced method used at some places in Egypt is farming fish next to the plants in a closed cycle. This allows the plants to benefit from the ammonia excreted by the fish, helping the plants to grow better and at the same time eliminating the need for changing the water for the fish, because the plants help to keep it clean by absorbing the ammonia. The fish also get some nutrients from the roots of the plants as well as oxygen.

See also

Ecovillages are socially, economically and ecologically sustainable villages of 50 to 150 people. ... A more sustainable city, or Eco-city, has fewer inputs (of energy, water, food etc) and fewer waste products (heat, air pollution, water pollution etc) than a less sustainable city. ... A roof garden is any garden on the roof of a building. ... The Try2004 Hyperstructure or Megacity as featured on the Discovery Channels Extreme Engineering programs. ...

References

External links

Categories: Gardening | Landscape | Roofs Image File history File links Commons-logo. ... Wikimedia Commons logo by Reid Beels The Wikimedia Commons (also called Commons or Wikicommons) is a repository of free content images, sound and other multimedia files. ... Parkland in Burkina Faso: Sorghum grown under Faidherbia albida and Borassus akeassii near Banfora, Burkina Faso Agroforestry combines agriculture and forestry technologies to create more integrated, diverse, productive, profitable, healthy and sustainable land-use systems. ... Appropriate technology is the term used to describe objects which meet the needs of the local people and the environment in which they live. ... It has been suggested that this article or section be merged with Off-the-grid. ... Cob building dated 1539 in Devon, England. ... Composting toilets use biological processes to deal with the disposal and processing of human excrement into organic compost material. ... Ecoforestry is forestry that emphasizes holistic practices which strive to protect and restore ecosystems1 instead of traditional forestry that maximizes economic productivity. ... Ecological economics is a branch of economics that addresses the interdependence and co-evolution between human economies and natural ecosystems. ... Earth covered farm houses in Keldur, Iceland. ... Development economics is a branch of economics that deals with the study of macroeconomic causes of long term economic growth, and microeconomics; the incentive issues of individual households and firms, especially in developing countries. ... Environmental design is the process of addressing environmental parameters when devising plans, programs, policies, buildings, or products. ... Timber Exploitation of natural resources is an essential condition of the human existence. ... Food security is a term used in development and humanitarian aid. ... Forest gardening (also known as 3-Dimensional Gardening) is a food production and land management system based on replicating woodland ecosystems, substituting trees (such as fruit or nut trees), bushes, shrubs, herbs and vegetables which have yields directly useful to mankind. ... It has been suggested that this article or section be merged with Sustainable architecture. ... Green Chemistry is the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances. ... Green Computing is the design of technological and computing products that reduce the use of hazardous substances and radiation. ... Green Gross Domestic Product (Green GDP) is an index of economic growth with the environmental consequences of that growth factored in. ... Green Map of Cambridge, Massachusetts Green Maps are environmentally themed maps which are usually created as a grassroots effort with a symbol set licensed from the non-profit Green Map System. ... Humanure is a neologism designating human waste (feces and urine) that is recycled via composting for agricultural or other purposes. ... This is a list of companion plant relationships. ... This is a list of repellent plants. ... The living machine at Oberlin College with a settlement tank in the foreground and filtering tanks in the background The concept of living machines represents a particularly interesting variant on intelligent machines, and has mostly been associated with water treatment systems that make use of natural bioremediation processes such as... Mycoremediation is a form of bioremediation, the process of using microbes to return an environment (usually soil) contaminated by pollutants to a less contaminated state. ... Natural building involves a range of building systems and materials that place major emphasis on sustainability. ... Permaculture Mandala summarising the ethics and principles of permaculture design. ... Rammed Earth is an old building material that has seen a revival in recent years as people seek low-impact building materials and natural building methods. ... Ancient technique re-introduced by Masanobu Fukuoka. ... Autonomy is the condition of something that does not depend on anything else. ... Sheet composting is the process of composting organic matter directly onto the soil as a mulch and letting it decay there, rather than in a heap. ... It has been suggested that this article or section be merged with Solar Tower. ... Straw-bale construction is a building method that uses straw bales as structural elements, insulation, or both. ... Sustainability is an attempt to provide the best outcomes for the human and natural environments both now and into the indefinite future. ... Sustainable agriculture integrates three main goals: environmental stewardship, farm profitability, and prosperous farming communities. ... It has been suggested that Green design be merged into this article or section. ... Sustainable development is a collection of methods to create and sustain development which seeks to relieve poverty, create equitable standards of living, satisfy the basic needs of all peoples, and establish sustainable political practices all while taking the steps necessary to avoid irreversible damages to natural capital in the long... Sustainable forest management is a sub-set of sustainable development. ... The earliest mention of the phrase sustainable industries appeared in 1990 in a story about a Japanese group reforesting a tropical forest to help create sustainable industries for the local populace. ... Sustainable living might best be defined as a lifestyle that could, hypothetically, be sustained unmodified for many generations without exhausting any natural resources. ... The Natural Step is a systematic definition of sustainability developed by Swedish scientist, Karl-Henrik RobÃ¨rt. ... Vermicompost (also called Worm Compost, Vermicast, or Worm Manure) is end product of the breakdown of organic matter by special varieties of earthworms. ... A windcatcher (Badgir; Ø¨Ø§Ø¯Ú¯ÛŒØ±) is a traditional Persian architectural device used for many centuries to create natural ventilation in buildings. ... Zoning in Permaculture design refers to a method of ensuring that elements are correctly placed. ... Image File history File links Crystal_128_energy. ... In physics and engineering, energy conversion is any process of converting energy from one form to another. ... It has been suggested that Comparison of power plants be merged into this article or section. ... This does not cite its references or sources. ... For the physical concepts, see conservation of energy and energy efficiency. ...

Contents

Benefits of green roofs GA_googleFillSlot("encyclopedia_square");